LEED vs. Passive House: What’s the difference?

As a Leadership in Energy and Environmental Design Accredited Professional, I readily defend LEED’s standard and certification to critics who question its alleged greenness and whether it lives up to its hype.

“You get points for including bike parking spaces?” they protest. “C’mon!”

Nonetheless, I stand by the usefulness of LEED certification and believe it serves a useful purpose even if it only increases dialogue and awareness about sustainable building.

With that said, recent conversations have led me to explore other types of sustainable building standards and methods. I have been very impressed with Passive House (aka Passivhaus), a building standard from Germany that is an exciting option for builders, homeowners and developers.

Passive House’s basic premise is to lower energy loads by using building mass with the goal of eliminating building systems.

“Passive” does not refer exclusively to passive solar heating, often a component of Passive House. The standard goes beyond and requires very high levels of insulation with minimum thermal bridges and thorough consideration of the utilization of solar and internal gains. Passive House looks to exceptional levels of air tightness, which differs from other building techniques. Contrary to what some may think about air tightness, all Passive House buildings boast first-class indoor air eminence because most of them use heat recovery ventilation systems.

Unfortunately, Passivhaus is victim to a poor translation. The German word “haus” is not limited to single-family residences. For example, a “gasthaus” is an inn or hotel, not literally a “guest house” as a direct translation might infer. The Passive House standard can be used for all types of buildings, as is the case in Europe.

I know of three Passive House projects in progress. The first is a remodel of Passive House advocate Tad Everhart’s home. The other two are new construction and being driven by Milos Jovanovic and Robert Hawthorne, both alumni of GBD Architects.

First profiled in the DJC last year, Jovanovic’s project is in Hood River. Construction of the Shift House is scheduled to begin construction this spring.

Hawthorne’s project, located in Northeast Portland and called the Corehaus, is scheduled to be completed this spring. (For full disclosure, Robert Hawthorne is my husband.)

These are three lonely projects in a sea of LEED certified buildings. Portland boasts the most LEED buildings per capita and claims to be the leader in green building.

But why are there so few Passive Houses?

LEED seems sexier. It focuses on broad categories that can showcase features to the general public. There are five areas assessed in LEED: water efficiency, sustainable sites, materials and resources, indoor environmental quality, and energy and atmosphere.

Passive House is easier to explain, but its features are not easily displayed. Its primary focus is energy efficiency, which isn’t particularly sexy when all that can be shared with someone is what type of foam insulation is being used (and that ends up being hidden behind walls). However, actual energy savings can be demonstrated, such as through a $5 electricity bill for January.

Also, photovoltaic sunshades or roof-mounted wind turbines are definitely showier versus Passive House’s goal to achieve energy efficiency so great that solar arrays, wind turbines or other complex systems are not needed.

Perhaps another reason that Passive House has not caught on is because the standard is location- and climate-specific. LEED does not change based on geographic location. Although the U.S. Green Building Council says LEED is moving toward climate-specific certification, its current point system awards the same points for projects in any region, even though features’ impacts may be completely different.

Builder preferences also heavily influence LEED points pursued. With Passive House, however, either the standard is achieved or it isn’t.

So, which is better?

There is a strong argument that Passive House is the better standard for sustainable development. This is because a building’s biggest impact is its energy usage, and building costs are about the same when compared to LEED buildings (although like all building costs, this depends on the builder and owner).

LEED buildings are found to use 25-30 percent less energy than non-LEED buildings. Passive House buildings can slash the heating energy consumption of buildings by up to 90 percent, and overall energy consumption by 60 to 70 percent.

LEED does not require any minimum air changes per hour, even though building leakage contributes greatly to energy loss. Passive House requires less than or equal to 0.6 ACH at 50 Pascal pressure, which is 10 times tighter than Energy Star.

All in all, the Passive House standard takes a big bite from a building’s impact on the environment.

LEED and Passive House do not preclude each other – a building can obtain LEED certification and also meet the Passive House standard. Some have said LEED is ahead simply because it has been around longer.

If Portland is serious about remaining the green building leader, we should encourage and utilize innovative new standards for sustainable development. Let’s hope it does not take too long before other standards start gaining ground.

Monique Lee Hawthorne is an associate in the Portland office of Davis Wright Tremaine LLP and a LEED Accredited Professional. Her practice focuses on sustainable development. Contact her at 503-241-2300 or moniquehawthorne@dwt.com.

18 comments

Thanks for an article on Passive House. This is a great standard for building, and a good tool for working towards sustainability in our housing stock.

Passive House, as good as it is, only really addresses “Energy and Atmosphere” portion of LEED. It has nothing to do with other sustainable design goals such as water conservation, materials efficiency, site development etc. To compare LEED and Passive House is a real apples-to-oranges thing, and means little. A more fair comparison is Passive House to Energy Star Homes, in which case Passive House is an order of magnitude more effective in reducing energy use, and clearly a more stringent standard.

I disagree with claim that LEED does not change based upon geographic location or climate. The fact is that LEED for Homes’ offers the most credit points for the Energy and Atmosphere (EA) division, and when using the EA performance path this is directly related to the HERS index energy rating of the home. The HERS index is climate specific, relating home energy use versus climate zone requirements per the IECC. A home built in a cold climate must be much more insulated than if it was built in a warm climate to reach the same HERS index. Even if using the EA prescriptive path, building envelope features are tied to IECC climatic requirements. LEED therefor requires higher thermal efficiency in cold climates than in moderate climates to achieve equal credits. I do think LEED could do better – I would require the EA performance path for all homes (eliminate the prescriptive path option), and give even greater weight to the EA credits.

If someone really wants to build green, they should be looking at using Passive House in conjunction with LEED for Homes. These compliment each other, and any Passive House should do very well in LEED Energy and Atmosphere. By addressing the other LEED credits in design and construction, the resulting home should really be an excellent example of sustainable development.

I compare LEED and Passive House because of my exploration of different techniques. I agree that comparing all of LEED to Passive House may be difficult as you rightly point out since LEED covers more areas (which I do mention). However, my comparison is based on the fact that a building’s largest environmental impact is energy consumption. Therefore if our goal is decrease a building’s impact, LEED goes so far in its requirements but Passive House goes further.

To your point regarding location/climate specific, many of the LEED credit points awarded in EA are not prerequisites, meaning that you can go after them, but you wouldn’t be penalized for not attaining them. In Passive House, the standards (or LEED equivalent of prerequisites) actually change depending on your location. I’ll take a look at LEED Homes to review, it’s be awhile since I looked at LEED Homes. I studied LEED for New Construction and will review also, but my recollection is that LEED-NC isn’t region specific and that the USGBC is working to create one that is region/climate specific. Nonetheless, we can agree that LEED could do better.

I’m glad you agree with me that LEED and Passive House can work together. LEED registration costs are really expensive though, and may be cost prohibitive. A few small builders I’ve spoken with have decided to forgo due to costs, but are actually keeping very true to LEED requirements in the other categories.

Monique,
Thanks for an excellent article comparing different ratings systems, a topic often talked about as we evaluate where best to put our precious building and energy resources. One clarification to a good description of Passive House is that “mass” is not really a factor in design of such buildings. It is true that mass can help mitigate temperature swings, but experience has shown that very low heat loss and gain are more significant and moderate temperature very well even in the absence of building mass.
The comparison of LEED and Passive House is well stated in that they can be used in complement, with low energy design being the energy component of LEED design. For me, as an architect and Certified Passive House Consultant, I will focus on reducing energy demand primarily, while taking advantage of lessons learned from LEED focused design to employ best practices in materials and other resources.
Thank you for a clear and informative article.
Joe Giampietro, Seattle

Thank you for your comments. And, way to go on being on the cutting edge with the Certified Passive House Consultant designation. That is quite an accomplishment given the rigorous course work involved!